node, express, jade: How to process form data

Is there any best practise code pattern how to process HTML form data with express and jade templates? I was wondering, if it would make sense to use a PHP like self calling loop of the form template, say in your router script you have two handler for the same route, one for GET and the other for POST requests. Something like:

exports.getHandler = function(req, res){
  res.render('/formhandling/', {mode: "form-filling"});
}

exports.postHandler = function(req, res){
  res.render('/formhandling/', {mode: "form-processing"});
}

and the jade template might look like

extends layout

block content

  h1 #{title}

  if mode == "form-processing"
    p Form data processed...

  else
    form(name="", method="post", action="/formhandling/")
    ...

Does that make any sense or did I get something completely wrong?

I feel like you could just use jQuery to hide the form after the user submitted, instead of rendering the response again. If you want to do any processing of the form on the server side, you can do that in your app.js.

app.get('/', routes.form);
app.post('/', function(res,req){
    /* form processing here
       you could also do this with an external route */
});

Edit: Also, see my answer on this question